Find the Derivative of Y with Respect to the Appropriate $y = 7 \tanh ^ { - 1 } ( \cos x )$

Multiple Choice

Find the derivative of y with respect to the appropriate variable.
- $y = 7 \tanh ^ { - 1 } ( \cos x )$

A) $\frac { - 7 } { \sin x }$
B) $\ln \left( \frac { 1 } { \sqrt { 1 - x ^ { 2 } } } \right) \sin x$
C) $\frac { - 7 } { \cos x }$
D) $\frac { - 7 \sin x } { 1 + \cos ^ { 2 } x }$